Jamaica have been warned they risk being expelled from the 2016 Olympics if they fail to overhaul their drug-testing programme.

The World Anti-Doping Agency (Wada) has urged Jamaica's government to act on claims by a senior ex-employee of the Jamaica Anti-Doping Commission (Jadco) that it is turning a blind eye to possible drug cheats with inadequate testing procedures.

Renee Anne Shirley, former executive director of Jadco, claims Jamaica's politicians and administrators failed to address her concerns before she left her position in February, having joined shortly before London 2012. Only one out-of-competition drugs test was administered by Jamaica in the five months leading up to the Olympics, something Wada have confirmed they were aware of.

Shirley insists the five positive tests returned by Jamaican athletes, including Asafa Powell, in the buildup to this month's World Championships in Moscow were a "disaster" waiting to happen, and said: "They (Jadco) believe Jamaica does not have a problem".

Jadco could now be deemed non-compliant with the Wada code, meaning Jamaica risk missing out on the next Olympics and other major competitions.

"Our normal approach if we have issues falling into the category of either complaint or concern is to try to work with the particular signatory - in this case the Nada [national anti-doping agency] - and remedy it," Wada director general David Howman said.

"If nothing happens, we can ask our board to declare any of the signatories non-compliant and that has implications as to whether teams from the country would be admitted into various events.

"We report the non-compliance to people who can then consider whether other sanctions ought to follow. That would be the IOC [International Olympic Committee] and IAAF [International Association of Athletics Federations] and so on."

Shirley had expressed her concerns writing for Sports Illustrated this week. Howman added: "We were certainly concerned by the comments and would anticipate that the government and the agency itself would be appropriately responding.

"It's serious. And I think that if responsible people in Jamaica are looking at it then they will address it. I would be disappointed if they didn't. But, certainly, if there's a lack of response then it's something that we at Wada would want to take up with the Jamaican government."